Max length of linear rod?

[MrBean]

What in your opinions would be the maximum useable length of 25mm, unsupported precision ground rod. I'm mulling over some ideas for a planned second CNC. This rod would be supporting a moving gantry.

I know this question is a bit "fuzzy". I.E. How much deflection I can tollerate. How heavy is the gantry/router spindle. etc....etc...

I'd plan to double clamp both ends. Say, two clamps 50mm spacing at each end. I don't know how much weight it'll be supporting as I'm just tossing some ideas around at the moment and don't have any specifics.

Anyone got any "real world" experience with 25mm rod, or have any, weight/deflection specs.

Cheers. Terry.....

[jeffs555]

Go here and download BeamBoy. http://www.geocities.com/richgetze/ Run it and pick a length for your rod. Then click on Beam>Properties>Calculate, and set it for a solid 25mm rod. Then do Feature>Add Feature>Add Support and add a support at each end.(cantilever since you are rigidly supporting the rod at each end) Then you can do Feature>Add Load to put some load on, and then click Calculate and you will see the deflection.

[MrBean]

Cheers. Just what I needed.

Many thanks.

Regards Terry.....

[debogus]

That is cool ,should come in handy.

Dave